12 research outputs found
Toward an understanding of collective intellectual humility
The study of intellectual humility (IH), which is gaining increasing interest among cognitive scientists, has been dominated by a focus on individuals. We propose
that IH operates at the collective level as the tendency of a collective’s members to attend to each other’s intellectual limitations and the limitations of their collective cognitive efforts. Given people’s propensity to better recognize others’ limitations than their own, IH may be more readily achievable in collectives than individuals. We describe the socio-cognitive dynamics that can interfere with collective IH and offer the solution of building intellectually humbling environments that create a culture of IH that can outlast the given membership of a collective. We conclude with promising research directions
Vascular smooth muscle cells remodel collagen matrices by long-distance action and anisotropic interaction
While matrix remodeling plays a key role in vascular physiology and pathology, the underlying mechanisms have remained incompletely understood. We studied the remodeling of collagen matrices by individual vascular smooth muscle cells (SMCs), clusters and monolayers. In addition, we focused on the contribution of transglutaminase 2 (TG2), which plays an important role in the remodeling of small arteries. Single SMCs displaced fibers in collagen matrices at distances up to at least 300 μm in the course of 8–12 h. This process involved both ‘hauling up’ of matrix by the cells and local matrix compaction at a distance from the cells, up to 200 μm. This exceeded the distance over which cellular protrusions were active, implicating the involvement of secreted enzymes such as TG2. SMC isolated from TG2 KO mice still showed compaction, with changed dynamics and relaxation. The TG active site inhibitor L682777 blocked local compaction by wild type cells, strongly reducing the displacement of matrix towards the cells. At increasing cell density, cells cooperated to establish compaction. In a ring-shaped collagen matrix, this resulted in preferential displacement in the radial direction, perpendicular to the cellular long axis. This process was unaffected by inhibition of TG2 cross-linking. These results show that SMCs are capable of matrix remodeling by prolonged, gradual compaction along their short axis. This process could add to the 3D organization and remodeling of blood vessels based on the orientation and contraction of SMCs
Selective oxidation of methane to methanol on dispersed copper on alumina from readily available copper(ii) formate
The direct conversion of methane to methanol attracts increasing interest due to the availability of low-cost methane from natural gas. Significant steps in that direction have already been achieved, using a stepwise chemical looping approach employing zeolites, but these materials have limited industrial relevance, because of low methanol productivity and relatively high materials cost. We therefore investigated the reactivity of copper supported on γ-Al2O3 prepared by common synthetic routes, namely incipient wetness impregnation and specific adsorption. All materials showed reactivity for the partial oxidation of methane under mild conditions (6 bar, 200 °C), with increasing reactivity as the copper loading increases, leading to a maximum methanol yield of 15 μmol CH3OH g−1. A combination of spectroscopic techniques (UV-vis, XAS, EPR, TPR) allowed the assignment of the reactive species at low loading to the previously reported monomeric [CuO(OH)]− sites. This straightforward synthetic approach and spectroscopic characterization of the Cu(II) speciation can be applied to a wide range of oxide supports.ISSN:2044-4753ISSN:2044-476
CH4-to-CH3OH on Mononuclear Cu(II) Sites Supported on Al2O3: Structure of Active Sites from Electron Paramagnetic Resonance
The selective conversion of methane to methanol remains one of the holy grails of chemistry, where Cu-exchanged zeolites have been shown to selectively convert methane to methanol under stepwise conditions. Over the years, several active sites have been proposed, ranging from mono-, di- to trimeric Cu(II). Herein, we report the formation of well-dispersed monomeric Cu(II) species supported on alumina using surface organometallic chemistry and their reactivity towards the selective and stepwise conversion of methane to methanol. Extensive studies using various transition alumina supports combined with spectroscopic characterization, in particular electron paramagnetic resonance (EPR), show that the active sites are associated with specific facets, which are typically found in gamma- and eta-alumina phase, and that their EPR signature can be attributed to species having a tri-coordinated [(Al2O)CuIIO(OH)]-,T-shape geometry. Overall, the selective conversion of methane to methanol, a two-electron process, involve two of these isolated monomeric Cu(II) sites that play in concert
Methane-to-Methanol on Mononuclear Copper(II) Sites Supported on Al2O3: Structure of Active Sites from Electron Paramagnetic Resonance
The selective conversion of methane to methanol remains one of the holy grails of chemistry, where Cu-exchanged zeolites have been shown promote this reaction under stepwise conditions. Over the years, several active sites have been proposed, ranging from mono-, di- to trimeric CuII. Herein, we report the formation of well-dispersed monomeric CuII species supported on alumina using surface organometallic chemistry and their reactivity towards the selective and stepwise conversion of methane to methanol. Extensive studies using various transition alumina supports combined with spectroscopic characterization, in particular electron paramagnetic resonance (EPR), show that the active sites are associated with specific facets, which are typically found in γ- and η-alumina phase, and that their EPR signature can be attributed to species having a tri-coordinated [(Al2O)CuIIO(OH)]− T-shape geometry. Overall, the selective conversion of methane to methanol, a two-electron process, involves two monomeric CuII sites that play in concert.ISSN:1433-7851ISSN:1521-3773ISSN:0570-083
The effectiveness of mediolateral episiotomy in preventing obstetric anal sphincter injuries during operative vaginal delivery: a ten-year analysis of a national registry
Obstetric anal sphincter injuries (OASIS) are associated with an increased risk of faecal incontinence after vaginal delivery. The aim of this retrospective population-based cohort study was to assess whether mediolateral episiotomy is associated with a reduction in the rate of OASIS during operative vaginal delivery. We used data from the Dutch Perinatal Registry (Perined) that includes records of almost all births between 2000 and 2010 in The Netherlands. In a cohort of 170,969 primiparous and multiparous women whose delivery was recorded, we estimated the association between mediolateral episiotomy and OASIS following both vacuum and forceps deliveries using univariate and multivariate logistic regression analysis. The incidences of OASIS following vacuum delivery in 130,157 primiparous women were 2.5% and 14% in those with and without a mediolateral episiotomy, respectively (adjusted OR 0.14, 95% CI 0.13-0.15), and in 29,183 multiparous women were 2.0% and 7.5%, respectively (adjusted OR 0.23, 95% CI 0.21-0.27). The incidences of OASIS following forceps delivery in 9,855 primiparous women were 3.4% and 26.7% in those with and without a mediolateral episiotomy, respectively (adjusted OR 0.09, 95% CI 0.07-0.11), and in 1,774 multiparous women were 2.6% and 14.2%, respectively (adjusted OR 0.13, 95% CI 0.08-0.22). The use of a mediolateral episiotomy during both vacuum delivery and forceps delivery is associated with a fivefold to tenfold reduction in the rate of OASIS in primiparous and multiparous wome
Evaluation of two vaginal, uterus sparing operations for pelvic organ prolapse:modified Manchester operation (MM) and sacrospinous hysteropexy (SSH), a study protocol for a multicentre randomized non-inferiority trial (the SAM study)
BACKGROUND: Pelvic organ prolapse (POP) affects up to 40% of parous women which adversely affects the quality of life. During a life time, 20% of all women will undergo an operation. In general the guidelines advise a vaginal operation in case of uterine descent: hysterectomy with uterosacral ligament plication (VH), sacrospinous hysteropexy (SSH) or a modified Manchester operation (MM). In the last decade, renewed interest in uterus sparing techniques has been observed. Previous studies have shown non-inferiority between SSH and VH. Whether or not SSH and MM are comparable concerning anatomical and functional outcome is still unknown. The practical application of both operations is at least in The Netherlands a known cause of practice pattern variation (PPV). To reveal any difference between both techniques the SAM-study was designed. METHODS: The SAM-study is a randomized controlled multicentre non-inferiority study which compares SSH and MM. Women with symptomatic POP in any stage, uterine descent and POP-Quantification (POP-Q) point D at ≤ minus 1 cm are eligible. The primary outcome is the composite outcome at two years of absence of prolapse beyond the hymen in any compartment, the absence of bulge symptoms and absence of reoperation for pelvic organ prolapse. Secondary outcomes are hospital parameters, surgery related morbidity/complications, pain perception, further treatments for prolapse or urinary incontinence, POP-Q anatomy in all compartments, quality-of-life, sexual function, and cost-effectiveness. Follow-up takes place at 6 weeks, 12 and 24 months. Additionally at 12 weeks, 6 and 9 months cost-effectiveness will be assessed. Validated questionnaires will be used and gynaecological examination will be performed. Analysis will be performed following the intention-to-treat and per protocol principle. With a non-inferiority margin of 9% and an expected loss to follow-up of 10%, 424 women will be needed to prove non-inferiority with a confidence interval of 95%. DISCUSSION: This study will evaluate the effectiveness and costs of SSH versus MM in women with primary POP. The evidence will show whether the existing PPV is detrimental and a de-implementation process regarding one of the operations is needed. TRIAL REGISTRATION: Dutch Trial Register (NTR 6978, http://www.trialregister.nl ). Date of registration: 29 January 2018. Prospectively registered
Divided access and the spatial polarization of housing wealth
Recent research has pointed to increasingly divided housing access across advanced economies. This reflects growing labor market inequality and rising intergenerational divides amplifying the importance of parental resources. At the same time, an increasing spatial polarization of housing markets has driven divergence between high-gain versus low-gain submarkets. This paper confronts how divided access to housing collides with growing spatial inequality in housing markets. The research turns to the Netherlands, drawing on full-population register data. First, GIS mapping exposes spatial polarization in house-value development. Second, household-level modeling demonstrates the impact of income, employment position and parental wealth in divided access to housing submarkets. Taken together, spatial polarization and differentiated access appear fundamental to driving inequalities in housing wealth accumulation